Final answer:
The relationship between lines CD and AB is orthogonal (option C), meaning they are perpendicular to each other.
Step-by-step explanation:
The geometric term that represents the relationship between lines CD and AB is Orthogonal. Orthogonal vectors are two vectors that have directions that differ by exactly 90°, which is synonymous with perpendicular vectors. In this case, line CD is perpendicular to line AB, forming a 90° angle between them.
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